土石围堰分期设计与施工在工程中的应用
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摘要
通常情况下,土石围堰应按照挡水时段内对应最大洪水的特定防洪标准进行设计,保证挡水时段内围堰断面不变,并要求最大断面围堰的背水侧坡脚与永久建筑物基础开挖边坡线有一定的距离,以满足基础开挖边坡稳定的要求。结合施工进度安排和合理的施工组织,设计考虑将土石围堰的挡水时段进行分期,按照分期填筑或分期拆除的方式实施围堰,在保证围堰的背水侧坡脚与基础开挖边坡线距离不变的前提下,可通过缩小围堰基坑侧断面的方式,缩短围堰与永久建筑物的距离,从而达到减少围堰临时占地、减少围堰侵占河道过水断面、节省投资等目的。土石围堰分期设计与施工在上海新石洞水闸工程外河围堰、安徽高建垾泵站工程外河围堰中均有良好的应用,为今后类似工程围堰的设计与施工提供了有益的参考。
Under the normal conditions, the earth-stone cofferdam should be designed according to the specific flood control standard corresponding to the maximum flood in the period of water retaining so as to ensure that the section of the cofferdam remains unchanged in the period of water retaining, and the back water side slope toe of the maximum section cofferdam should have a certain distance from the slope line of the foundation excavation of the permanent building in order to meet the requirements of the stability of the foundation excavation slope. Combined with the construction schedule and reasonable construction organization, the retaining period of the earth-rock cofferdam should be considered to divide into stages during the design. And the cofferdam should be filled or dismantled by stages. On the premise that thedistance between the backwater side slope toe of cofferdam and the excavation slope line of foundation remains unchanged, the distance between cofferdam and permanent building can be shortened by the method of reducing the side section of cofferdam foundation pit so as to decrease the temporary land occupied by cofferdam, to reduce the cross section of river channel encroached by cofferdam, and to save the investment.The design and construction of earth-rock cofferdam by stages have been well applied in the outer river cofferdams of Shanghai Xinshidong Sluice Project and Anhui Gaojianlai Pumping Station Project, which can provide the useful reference for the design and construction of the similar cofferdams in the future.
Under the normal conditions, the earth-stone cofferdam should be designed according to the specific flood control standard corresponding to the maximum flood in the period of water retaining so as to ensure that the section of the cofferdam remains unchanged in the period of water retaining, and the back water side slope toe of the maximum section cofferdam should have a certain distance from the slope line of the foundation excavation of the permanent building in order to meet the requirements of the stability of the foundation excavation slope. Combined with the construction schedule and reasonable construction organization, the retaining period of the earth-rock cofferdam should be considered to divide into stages during the design. And the cofferdam should be filled or dismantled by stages. On the premise that thedistance between the backwater side slope toe of cofferdam and the excavation slope line of foundation remains unchanged, the distance between cofferdam and permanent building can be shortened by the method of reducing the side section of cofferdam foundation pit so as to decrease the temporary land occupied by cofferdam, to reduce the cross section of river channel encroached by cofferdam, and to save the investment.The design and construction of earth-rock cofferdam by stages have been well applied in the outer river cofferdams of Shanghai Xinshidong Sluice Project and Anhui Gaojianlai Pumping Station Project, which can provide the useful reference for the design and construction of the similar cofferdams in the future.
引文
[1] SL645-2013,水利水电工程围堰设计规范[S].
[2] SL303-2017,水利水电工程施工组织设计规范[S].
[2] SL303-2017,水利水电工程施工组织设计规范[S].